Automatic overhead door



Sept- 25, 1951 K. E. JoHANsoN 2,568,808

AUTOMATIC OVERHEAD DOOR 1 INVENTGR Karl EJO/zanjar( Sept. 25, 1951 K. E. JoHANsoN AUTOMATIC OVERHEAD DooR 6 Sheets-Sheet 2 Filed March 22, 1946 Sept. 25, 1951 K. E. v.loHANsoN 2,568,808

AUTOMATIC OVERHEAD D003 Filed March 22, 194e e sheets-sheet :s

Sept. 25, 1951 K. E. JoHANsoN AUTOMATIC OVERHEAD DOOR Filed March 22, 194e 6 Sheets-Sheet 4 Of O m13 m Sept- 25, 1951 K. E. JoHANsoN 2,568,808

AUTOMATIC OVERHEAD DoQR Filed March 22.- 1946 6 Sheets-Sheet 5 /65 u /6/94171914 I m2 /8 g/Mq, INVENToR.

PW @wam @j Sept 25, 1951 K. E. `JOHANsoN f 2,568,808

' AUTOMATIC OVERHEAD DOOR Filed March 22, 194e 6 sheets-sheet 6 U2, Hy. l5

IN VEN TOR.

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Patented Sept. 25, 1.1951

AUTOMATIC OVERHEAD DOOR Karl E. Johanson, Oak Lawn, Ill.

Application March 22, 1946, Serial No. 656,494

6 Claims. (Cl. 268-59) This invention relates toA power-operated door Afor garages, factories, warehouses, and the like.

The main objects of this invention are to provide power-operated door structures having improved means for mounting the doors for shifting between closed and open positions; to provide improved counterbalancing means for such a door so that a minimum amount of power or force is required to shift the door between its open and closed positions; to provide improved draft means for causing the shifting of thedoor between its open and closed positions; to provide improved clutch mechanism for connecting said draft means with a source of power; to provide improved means for controlling the operation of said clutch means; to provide improved brake means synchronized with the shifting of said clutch mechanism to check and restrain the acltion of said draft means, when said clutchmechanism is retracted; and to provide improved means for automatically checking the movement of the door toward a closed position when it strikes an obstruction or reaches the limit of its travel to its fully closed position.

Alternate forms of draft means for poweroperated doors and various modifications of clutch mechanism for connecting such means to different types of motor suitable for opening and closing doors are shown in the accompanying drawings, in which:

Fig. 1 is a vertical sectional elevation showing the improved door construction and mounting means for power-operated doors of this kind;

Fig. 2 is an enlarged transverse, vertical, sec.k ftional detail taken on the line 2-2 of Fig. 1;

Fig. 3 is a cross-sectional detail taken on the line 3-3 of Fig. 2;

Fig. 4 is a partly sectional and partly elevational detail taken on the line 4-4 of Fig. 2, showing the preferred form of draft means by which the door is shifted between its open and closed positions; 1 p

Fig. 5 is a cross-sectional detail view taken on the line 5--5 of Fig. 2;

Fig. 6 is an enlarged horizontal sectional de tail view taken on the line 6 6 of Fig. 1 of one form of an interrelated clutch and brake mechanism for controlling the operative functioning of draft means through which the power of a unidirectional motor is transmitted for the opposite shifting of the door between its closed and open Fig. 8, showing the belt-controlled overloadv means whereby an overload switch is actuated to arrest further movement of the door, when its closing movement is checked by some obstruction in the doorway;

Fig. 10 is a diagrammatic view of the electrical circuit and switch mechanisms for controlling the operation of the clutch and brake mechanism shown in Fig. 6, and Figs. 7 and 8;

Fig. 11 is a sectional elevation of an adaptation of the clutch and brake mechanism, shown in Fig. 6, for use with a reversible motor;

Fig. 12 is a transverse sectional view, partly broken away, taken on the line l2-I2 of Fig. 11;

Fig. 13 is a sectional view taken on the line l3-I3 of Fig. 11.

Fig. 14 is a partly sectional and partly elevational detail of a modified form of an interrelated clutch and brake mechanism for controlling the operative functioning of the draft means through transmitted for the opposite shifting of the door between its closed and open positions;

Fig. 15 is an adaptation of the clutch and brake mechanism, shown in Fig. 14, for use with a reversible motor; and

Fig. 16 is a diagrammatic View of the electrical circuit and switch mechanisms for controlling the operation of the clutch and brake mechanism shown in Fig. 14. y

The improved door and power-operated draft mechanism therefor, shown in the accompanying drawings, comprises a door 20 equipped with a counterbalancing means 2l and arranged to be shifted between a vertically-disposed closed position and a horizontally-disposed overhead open position through the action of either a wormtype draft means 22 or a chain-and-sprocket draft means 23 adapted to be connected, through the medium of either an electrically-controlled mechanically-operated clutch and brake mechanism 24 or an electrically-controlled magnetically-operated clutch and brake mechanism 25, to a motor 2li.y

The door 20, which is of the sectional type, is suspended on transmission means 21 for movement along channel-shaped supports 28 under the action of either type of draft means 22 or 23.

Each of the door sections, below the upper section, is equipped with casters 29 operating in the vertical and overhead trackage 3U as the door moves between its closed and open positions, as shown in full and dotted outlines in Fig. 1.

The door transmission means 21 comprises a pinion and roller combination 3| secured at each end of a shaft 32 journaled in brackets 33 secured to the upper corners of the upper section of the door 20. The pinion-roller combination 3l is formed by mounting a pinion 34 between a flange' 35 formed on the collar 36 and a ring 31 which is secured to the flange 35, with the pinion in between, by means of pins 38. The collar 36 is keyed to the shaft 32 by means of a pin 39. The flange 35 and ring 31 thus serve as rollers adapted to travel on rails 40, a pair of which are clamped to each of the channel-shaped supports 28 with a rack 4I in between. By virtue of this arrangement the weight of the door, in its closed position, is suspended by the rollers on the rails 40. As the pinions 34 are caused to travel along the racks 4I the door is shifted between its closed and open positions.

The channel-shaped supports 28, by means of suitable brackets. are mounted horizontally along the ceiling from the door opening to a point slightly beyond the extreme travel of the door 2li,A in its horizontally-disposed open position.

The counterbalance 2l is in the form of a pair of drums 42 each mounted on roller bearings 43 supported on a tubular member 44. Each tubular member 44 is rotatably supported in a pair of L-shaped brackets 45 which are suspended from one of the respective ends of the channelshaped supports 28, at their forward ends adjacent the door opening. Cables` 46, connected at 41 to the lower corners of the bottom door section and at 48 (see Fig. 2) to the drums 42, are adapted to wrap around the respective peripheries of the drums as shown in Fig. 2. In each drum a at clock spring 49, of conventional form,

has the inner end hooked as shown at 58 (see Fig. and slipped through a slot 5I in hub member 44. The other end of the spring is fastened to the drum 42 as shown at 52. A pin 53, inserted through a flanged plate 54 on one of the brackets 45 and through registering apertures 55 in the hub member 44, permits the initial tensioning of the spring 49 so as to secure the proper counterbalancing of the door 26.

The worm type of draft means 22 is the preferred form. This comprises a shaft 56 extending parallel to and along one of the channelshaped supports 28 and has a spiral thread 51 formed thereon which meshes with a toothed follower 58, connected to the shaft 32.` The spirallythreaded shaft 56 is supported throughout its length in a tubular sheath 59 which lies on the bottom of one of the channel-shaped supports 28, inwardly of the combination rail 40 and rack 4I, and extends the full length of said support between the front wall of the doorway and the motor-and-clutch-mechani'sm housing 68. This sheath 59 is open along the upper part thereof to receive and guide the follower 58, as is most clearly shown in Fig. 2. Y

The spiral thread 51, on the shaft 56, terminates just short of the motor-and-clutch-mechanism housing 60. However, the shaft extends on through the housing and has the rear end thereof supported in a bearing 5| set into the rear wall of said housing 60. Intermediate the ends of the housing 66, a sleeve 62 is secured to the shaft 56 by means of pins 63.

The sleeve 62 affords support for a tube 64, the inner or forward. end of which is journaled on a bearing 65 secured to the forward end wall of the housing 68. The opposite or rear end of the tube 64 is internally recessed to receive a head 66, integral on the end of the sleeve 62, and exte-riorly threaded to receive a cap 61 which is thereby shiftable along the tube 64 so as to adjust the tension of a springl 68, interposed between the cap end and the sleeve head 66 which yieldingly holds the shaft 56 against axial movement for a purpose that presently will appear more fully. In order that the tube 64 may rotate with the shaft 56, but permit it to have relative axial movement, the tube 64 is slotted at 69 to receive rollers 18 supported on a pin 1I extending through the shaft 56 and the sleeve 62.

A hand Wheel 12, secured to the outer end o-f c the shaft 56, permits turning thereof in emergent situations, to move the door when, for some rea.- son, the electric senvice is temporarily interrupted.

The follower or carriage 58 has rollers 13 journaled thereon to bear against the under surface of the upper horizontal flange of the channelshaped support 28. As the shaft 56 is rotated the spiral thread 51 meshing with the row of teeth 14 formed on the undersideof the follower 58 moves the follower axially of the shaft 56. Thereupon, the pinions 34, of 'the pinion-roller combinations 3I, travel along the rack'4l and cause a movement of the door 28 between its open and closed positions.

The chain-and-sprocket draft means 23 comprises a pair of sprockets 15 and 16 journaled on one of the channel-shaped supports 26, adjacent opposite ends thereof, and connected by a chain 11. The sprocket 15 is driven by means off a belt and pulley combination 18 whereas the sprocket 16 positions the chain 11 for its connection to a follower 58 by means of a crank 19.y

The belt-pulley combination 18 includes grooved pulleys 88 and 8l connected by a V belt 82. The pulley 88 is connected to the sprocket 15 by means of a shaft 83. The pulley 8| is mounted -on a shaft 84 which is driven by a motor 26 through the medium of the clutch mechanism 24, as will appear more fully hereinafter.

The crank 19, lby Iwhich the chain 11 is connected to the follower 56', is pivoted at 85 tov one of the links in the sprocket chain 11 and at 86 to aV block 81 slidably mounted on the follower 58.V

The block 81 has a stem 88 extending through the rear lpart of the follower 58 and between the rear end of which and a anged nut 89 on said stem a spring 98 `is arranged. This spring normally urges the block 81 rearwardly on the follower 58' but permit-s it to shift forwardly thereof when the pivotal connection of the crank 19 is moving around the sprocket 18, as is indicated by dot-ted outlines in Fig. '1.

The follower 58', in addition to the rollersY 13 bearing against the upper flange of the support 28, has a roller 13 bearing against the 'rails 40.

A pin 9i on the hub of the crank 19' extends` into a slot 92 formed inthe forward face of the Y block 81. This limits the movement of the crank 19 so that if the overload-reverse causes the upper strand of the chain to move rearwardly the chain 11 will not be pushed up against the upper flange of support 28.

Intermediate the sprockets 15 and 16 is mounted an idler sprocket 93 which holds the sprocket chain 11 up away from the bottom of the channel-shaped support 28.

The y electrically-controlled mechanically-oper'- ated clutch and brake mechanism 24 is shown in two forms, one for use Iwith a unidirectional motor 26 (see Fig. 6) and the other for use vwith a reversible motor 26 (see Figs. 11, 12, and 13)'.

The clutch and brake mechanism 24, for use with the unidirectional motor, comprises'a pair of driving clutch members 94 and 95 and a pair of driven clutch members 96 and 91. For the worm-type draft mechanism 22, both pairs of clutch members, together with a brake drum 98, are mounted on the tube 64. For the chain and 5 sprocket draft mechanism 23 the pairs of clutch members and 'brake drum 98 are mounted on the shaft 84'. In either adaptation the clutch members ,and brake drum are operatively connected together by a lever and link mechanism 99, as will presently appear.

The driving clutch members 94 and 95 are rotatably mounted on the tube 64, or the shaft 84 (depending upon the type of draft mechanism), and have beveled gear teeth formed on their inner opposed faces which mesh with a beveled pinion connected to the motor 26.

The driven clutch members 96 and 91 are slidably keyed to collars I0| and |02 which, in turn, are secured by set-screws |03 to rotate with the -tube 64 or shaft 84, as the case may require. Friction rings |04 are secured to the faces of the driven clutch members 96 and 91 to engage the opposed faces of the driving clutch members 94 and 95, when the clutch members 96 and 91 are shifted axially tow-ard said driving clutch members 94 and 95. Being secured to rotate with the tube 64 or shaft 84 the collars |0| and |02 hold the driving clutch members 94 and 95 against axial movement on said tube or shaft.

The brake drum 98 may be a separate unit from the clutch mechanisms, as shown in Figs.k 6 and 8, and secured by a set-screw to the tube 64 or shaft 84 to rotate in unison with the driven clutch members 96 and 91, or it may be formed integral Iwith one of the driven clutch members. as shown in Figs. 11, 14, and 15. A friction-lined brak-e shoe |06 is mounted on a brake-shoe member |01 so as to be shifted into and out of engagement with the periphery of the brake drum 98.

`The lever and link mechanism 99, which controls the shifting of the driven clutch members 96 and 91 and the brake-shoe supporting mem- -ber |01, comprises a pair of levers |08 and |09 respectively connected to the driven clutch members 96 and 91 and which levers are in turn connected by links ||0, and ||2 to a rocker arm ,I |3 so as to relate the shifting of the brake shoe with the shifting of the clutch members 96 and 91. A spring I4 connects together levers |08 and |09 at their lower ends and, by reason of the connection of said levers to the brake shoe |06 and its engagement with the brake drum 98, normally holds the driven clutch members 96 and 91 out of engagement with lthe driving clutch members 94 and 95, Iwhen the electro-magnets ||5 and I|6, respectively connected to the levers |08 and |09, are de-energized.

The levers |08 and |09 are of the conventional Y-shaped form, s uch as appears from Fig. 7. At their upper ends they are pivotally supported on the housing 60 by means of pins ||1. Inwardly of these pivots the levers areconnected to the respective driven clutch members 96 and 91 by means of pins I8 on the conventional collars Il! (see Fig. '1)

The links III) and I|| have their upper ends pivotally connected to the respective levers |08 and |09 and their lower ends are connected together with the end of the link I|2, pivoted to the arm ||3, sothat any movement of either one of the levers |08 and |09 will actuate the brakeshoe supporting member |01, through the medium of the arm I I3 pivoted at |20 on the housing 60. The link ||2 is made adjustable, as shown at |2| (see Fig. 6), so that the shifting of the brake shoe supporting member |01 may be properly correlated with the shifting of either of the levers |08 or |09 under the influence of either the spring ||4 or the energized electro-magnets H5 or IIE.

The electro-magnets I5 and I6 are secured' to supports, mounted on the housing 60, on opposite sides of the levers I 08 and |09 respectively. The armatures |22 and |23 are pivotally connected to therespective levers drum are synchronized through the medium of a pair of co-acting levers |30 and |3|, pear presently.

The driving clutch member I 28 is free to rotate on the tube 64 and is axially shiftable thereon toward and away from the driven clutch member |29. It is connected by a belt |32 to a pulley on a reversible motor 26. is secured on the inner face of the driven clutch member |29 to engage the opposed face of .the driving clutch member |28. A spring |34, inter posed between a collar and a roller bearing ring |36, normally urges the driving clutch member |28 against the driven clutch member |29. The collar |35 is threaded on the tube 64 so that it may be shifted axially of the tube to adjust the tension of the spring |34. A set-screw |31 holds the collar |35 against axial movement on the tube 64, once it has been set to secure the desired tension of the spring |34.

The driven clutch member |29 is secured to rotate with the tube 64 by means of bolts |38.

The brake drum 98, in this modication, is in the form of a ange integral on the driven clutch member |29 and is adapted to be engagedv by the brake shoe |06 supported on the shiftable member |01. A spring |39, interposed between the brake shoe |06 and a piston cup |40 and slidably mounted in the member |01, is adapted to normally urge the brake shoe |06 into engagement with the brake drum 98.

The lever |30 is mounted to shift with or shift the driving clutch member |29, whereas the lever |3| is mounted to move with or move thebrakeshoe supporting member |01,

as will apsurfaces |4| and |42.

The lever I 30 is of the conventional Y-shaped form. At its upper end it is pivotally supported by a pin 43 to the housing 60 and is connected by pins |744 to a collar |45 of thel conventional type on the driving clutch member |28. When the spring |34 is free to act this lever |30 moves with the driving clutch member |28. On the other hand, when the spring |39 is free to act, so as to elevate the outer end of the lever |3|. the action of the cam roller |42 against the inclined cam surface I4| will cause the lever |30 to retract the clutch member |28,A against the normal pressure of the spring |34.

The lever |3| is also of the conventional .Y-

shaped form. At its outer end it is pivotally supported on the housing by means of a pin |46 and is connected to the brake shoe support |01 by pins |41. Adjacent to its outer end the lever |3| is connected to an armature |49 of the electro- |08 and |09 by; pins |24 and |25 set in elongated slots |26 andv The clutch and brake mechanism 24 for use A friction ring |331 Movement of the v lever |3| is adapted to eifect movement of the lever |30 through the action of the co-acting cam magnet |49 by means of a pin |50. The cammember |42, which is in the form of a roller, is mounted on the lever |3| intermediate the connection of said lever |3| to the brake shoe sup-- port |01 and the connection to the armature |45. In this modification (Fig. 11) the brake shoe support |01 is slidably supported on a post |5|, the stem |52 of which is adjustably secured to the housing 60 by means of a pair of nuts |53. The piston cup |40 rests against the forked upper end of post |5 and against 'an arm |54 of a belle crank lever |55. The arm |56 of said bell-crank lever |55 is connected, by an adjustable link |51, to a rocker arm |58 pivotally supported on the housing 60 by means of a link |59. The rocker arm |58, in turn, is connected to the overload control mechanism. as will appear more fully hereinafter. The pin |46 and the pivot for the bell=crank lever |55 are on a plate |55a slidably supported on the housing 60 and shiftable by means of the adjusting nuts |5511.

-, The electrically-controlled magnetically-operated clutch and brake mechanism 25 is shown in. two forms, one for use with a unidirectional motor 26 (see Fig. 14) and the other for use with a 'reversible motor 26 (see Fig.V 15). The two forms of the magnetic clutch 'and brake mechanisms are respectively comparable to the two forms of the electrically-controlled mechanicallyoperated clutch and brake mechanisms hereinbefore described, except that magnetic means for shifting the clutch members are substituted for the link and lever mechanisms. However, both forms of the electricallyecontrolled magnetic ally-operated clutch. and brake mechanism 25 are herein shown applied to the worm-type draft mechanism 22.

The clutch and brake mechanism 25, for use with the unidirectional motor (see Fig. 14) comprises a pair of driving clutch members 94' and 95 and a pair of driven clutch members 96' and 91.- Both pairs of clutch members, together with a brake drum 98', are mounted on tlietube 54.

' The engagement and disengagement of such clutch members is controlled by the electromagnets |60 and the engagement and disengagementV of the brake shoe with the brake drum is controlled by the co-action of a'spring |39 and an electro-magnet |49 suoli as' shown in Fig. 11. The driving clutch members 94' and 95' are rotatably mounted on the tube 64 and have beveled gear teeth formed on their opposed faces, which mesh with a beveled pinion I 00", Connected tothe' motor 26. Y u

Eacl of these driving clutch members 94 and 95 mounts an armature ring |6| and |62 on Spring discs IBBIseur'edto the hubs of the' members 94" and 9 5', outwardlyv of the gear faces. 'Ineses'pring discs permit aria'x'iai movement of the; armature ririgs I6! and |62 toward. and away fromv their respective co-acting driven clutch members 95` and 5'1" under the influence of the magnets I 60.

The. driven clutch members 9'6 and S31l are secures' to rotate with the' tube e4'. by means of set-screws |64. Friction rings |04 are secured to collars |65 threadingly supported o n the driven clutch members 95' and 91'. be rotated so as' to properly adjust the distance between the friction rings |04 and the armature rings |6|. Once adjusted, they arel held in place by means of set-screws |65.

VSeveral ofA the electro-magnets Ililr are set in the faces of the driven clutch members 95" and 31" with the cores positioned, so that' when ern-ir The collars |55 may gized., they Ywill attract the armature rings IBI and |62 and hold them in proper frictional enrgagement with the friction rings |04 on the driving clutch members 94' and 95. The electromagnets |50 are connected to a source of electricity through the medium of ring connectors |61 and |58 insulatingly mounted on the hubs of the respective driven clutch members 95' andlf.

The brake drum 98' is integrally formed with the driven clutch member 91' and is adapted to have a brake shoe |06 shifted into and out Iof engagement therewith by means of a lever |Y3l under the co-'action 'of the spring |39 and electromagnet |49,'as will more fully appear from a description of the modification 'shown in Fig. 15.

The modification of the electrically-controlled vrrla'gnetically-operated clutch and brake mechae nism 25 for use with a reversible motor, as is shown in Fig. 15, comprises a driving clutch mem ber |28 and a driven clutch member |29', the engagement and disengagement of which are controlled by the electro-magnets |60.

The driving clutch member |28 is journaled to rotate on the tube 64 and is driven by a belt |32 connected to a motor 26, in a manner similar te that shown in Fig. 12. Friction rings |33 are mounted on the face opposed to the driven clutch member |29'.

The driven clutch member |29 is secured to rotate with the tube 54 by means of bolts |38. An armature ring I6 'y is mounted oh the member 29' by means of a spring disc |63. which permits the armature l5 I to be drawn into frictional enfgagement with the friction rings |63' by the action of the electro-magnets |60. I

The electro-magnets |60` are connected toa source of power by means of a pair of ring con neotors |61', insulatingly supported o'n the' hub of the driving 'clutch member |28'.

The brake drum 98 is secured directly to the driven clutch member |29', to rotate in unisritherewith. It is adapted to have a brakeshoe |05, supported on the shftable member |01, moved into and out of engagement therewith by means of a lever |3l' under the co-.aetio'ri of the spring |39 and the electroem'agnet |49.

As explained in 'connection with the ntiodiiicar`` tion shown in Fig. 11, a spring |39 is interposed between the brake shoe |06 and a piston cup |40, slidably mounted in the member |01. The spring |39 isadapted to normally urge the brake shoe |06 into engagement with the brake drum 98',-V thereby shifting the lever |5|to the dotted position shown in Fig. 15, unless the force' f the spring |39 is counteracte'd by the electro-magnet |49, the' armature |48of which is connected by pin |59 to the lever |3|.

The lever I3 is of the' conventional Y`s`hapeg` such as shown in F'i-g. 13. The ends thereof are pivotally' supported on the housing 60 by" means' of a pin |45. Inwardly of said pivotal connection the lever |3 i" is connected to the brake shoe slipport |01 by means of pins |41.

The brake shoe mechanism in this modification (Fig. 15) has associated with it a bell-crank lever |55 which is connected byan adjustablev link |51 to a rocker arm |58 which, in turn,` is connected to the overload control mechanism, as4 has been previously described in connection with the' modification shown in Fig. 1.1'.

For either of the forms o fdraft means" tiene.

worm mecha sm 22 or the chain-sprocket mechanism 23') an overload switch cut-outrmechanism is provided. se met in ease the arcor', in'

being ioved toward' its closed position', strikes` a' 'obstruction the electrical circuit to the motor andthe clutch and .brake mechanism is instantly cut off. The overload -switch may be so constructed as to automatically reverse the operating mechanism and return the door to its fully open position.

The overload switch cut-out mechanism for the`worm-type of draft mechanism 22 comprises a member |69 mounted on the spirally-threaded lshaft 56 in position so that 'an axial shifting of the shaft 56 will cause the member |69 to shift a normally retracted switch-actuating member |10. The member |69 is secured to the shaft 56 intermediate the bearing 6| and the cap 61 for the tube 64.

Itis held in place by one or more collars |1|, keyed to the shaft by a set-screw |12, l

which permit axial adjustment of the member |69 relative to the shaft 56 so as to properly time the contact of the shaft-shifted member |69 with the switch-actuating member |10.

The switch-actuating member |10 is shown in different forms in Figs. 6 and 11. In Fig. 6a pin is normally urged by a spring |13 to shift the roller |14 into engagement with the cam surface |15 on the member |69. l InFig. 11 an arm isi pivoted at |16 and urged by gravity and a spring-actuated overload switch, hereinafter referred to, to hold the roller |14 in contact with the cam surface |15 on the member |69. The overload switch would be located so as to be actuated by the other end of the pin or arm |10.

The overload switch cut-out mechanism, for the chain-and-sprocket type of draft mechanism 23, comprises a member |69 pivoted on the channel-shaped support 28 at |11, intermediate g the reaches of the belt 82, so that rollers |18 and |19 contact the outside faces of the opposite reaches of said belt 82. A spring |80 normally Aur'gesthe member |69 to keep the roller |19 in contact with the underside of the lower reach of the belt 82. The strength of this spring |80 is such that, as shown in Fig. 9, it holds the lower reach of 'the belt out of the straight position whichit would normally occupy during the drive of the motor 26 to actuate the draft mechanism 23 to close the door. Therefore, if during the operation of the draft means 23 to close the door the door is obstructed, the temporary additional strain of the power applied to the lower reach of the belt 82 tends to move it toward the straight position shown in dotted outline in Fig. 9. This results in a movement of the member |69 against the action of the spring |80A which moves a switch-actuating member comparable to the switch-actuating member |10 shown in Figs. 6 and -11.

vThe'general character of the switch-controlled electrical-circuits, which determine the operation of the various modifications of clutch and brake mechanisms and consequently the opening and shutting of thedoor 20, is diagrammatically illustrated in Figs. 10 and 16. Fig. 10 diagrams the power and` control circuits for clutch and brake mechanism 24, such as shown in Fig. 6 or 8. Fig. 16 diagrams the power and control circuits for a clutch and brake mechanism 25, such as shown in Fig. 14.

As will be apparent from the previous description of these forms of clutch and brake mechanisms 24 and 25, the diagrams of Figs. 10 and 16 are arranged for a unidirectional motor. In cases where the clutch and brake mechanisms 24 and 25 of the types shown in Figs. 11 and 15, employing a reversible motor, the electrical circuits-would be the same as that shown in Fig. 16

the contactor switches |8| and |82, the action of which are controlled by the respective electromagnets |83 and |84, connected in the control circuit. The control circuit is provided with an up" switch |85, a down switch |86, a stop switch |81, an overload-reverse switch |88, a

limit switch |89,'and an isolating switch |90.

Interlocking switches |9| and |82 are also arranged in the control circuit, the opening and closing of which is determined by the shifting of the armatures for theelectro-magnets |83 and |84, respectively. The switches |85, |86, |81, and |88 are all double-pole single-throw spring-returned push-'button type. The switches |85 and |86 normally have one pole closed and the other open. Switch |81 has both poles normally closed. Switch |88 also has one pole closed and one pole open, but reversed in order as respects switches |85 and |86. Switches |89 and |90 are normally closed.

The operation of this improved door mechanism is as follows:

Regardless of which of the two poles of draft mechanism is used or which of the clutch and brake mechanism modications is employed for connecting the motor to the draft means, it is obvious that the pull or the push of the draft mechanism is applied to the door through the draft means acting on the follower 58 or 58. The pinions 34 meshing with the racks 4| ensure an equal movement of the rollers 35 and 31 at both sides of the door along the tracks 40. Assuming the door 28 is in its closed position, as shown in Fig. 1, the unreeling of the cables 46 from the drums 42 'has put the springs 49 under proper tension to counterbalance the door by reason' of the winding of the springs 49. VThis tension helps to facilitate the opening of the door and lessens the power .that would be required otherwise to start the door the instant the power of the motor 26 is applied, through the medium of the draft means 22 or 23. As the two pinion-roller combinations 34 move along the track and rack'combinations 40 and 4| the casters 29 move along the tracks 39. When the door has reached its full open position, asy shown in dotted outline in Fig. 1, the cable 46 has caused a slight rewinding of the spring 49 so that there is sufficient torque in thespring to give a boost to starting the dooron its movement toward its closed position, when'the power of the motor 26 is again applied for that purpose through the draft means 22 or 23. f

lRegardless of the type of draft means, or the modifications of the clutch and brake mechanisms that may be employed for shifting a door of this kind, the movement of the door is controlled by the vswitch mechanisms shown in the diagrammatic views of Figs. 10 and 16. When it is desired to elevate the door the Pup switch |85 is shifted. This closes the circuit to the electro-magnet |83 and causes a closing of the interlocking switch |9| and the contactor switch retract thev clutch member 96 and through the action of the spring I |4 shifts the lever |09 to bring the clutch member 91 into contact with the clutch member 95. The further shifting of. the lever |88, by the electro-magnet H5, causes the cause the retraction of the brake shoe |06 from the brake drum 98. Thereupon the motor` 25 revolves the spiral threaded shaft 56 and causes the follower 58v to move along the shaft 56 to open the door 20.

If it were desired to check the movement of the door, prior to itsreaching its full open position, a pushing of the stop switch |81 would break the circuit to the electro-magnet |83. Thereupon the armature thereof would be shifted., to open the contacter switch |8I, breaking the circuit to the electro-magnet I5 and to the motor. The spring ||4 would thereupon restore the levers |88 and |09 to their normal positions, the movement of which would be communicated through the links ||0, III, ||2, and the arm ||3 so as to again synchronize the shifting of the brake shoe |06 into contact with the brake drum 98 with the retraction of the clutch member 91, thus causing an instantaneous checking of the rotation of the shaft 56.

If, on the other hand, the door were allowed to complete its movement to a full open position, upon reaching that position suitable means on the door would engage and hold open a limit switch |89 (see Fig. 1) adjacent the inner end of the channel-shaped support 28. The shifting of the limit switch would break the circuit to the electromagnet |83 which would result in the clutch and brake operating mechanism 99 restoring the clutch and brake mechanism to the normal position shown in Fig. 6.

When itis desired to close the door, the down switch |86 would be pressed. This would cause an energization of the electro-magnet |84 resulting in a retraction of the armature therefor and thereby closing the interlocking switch |92 and the contacter switch |82. The results would be identical with what has previously been ex*- plained in connection with the switches I9| and |81. The energization of the electro-magnet ||6 would cause the armature |23 to shift the lever |99 to further retract the clutch member 91 which movement would be communicated through the spring ||4 to the lever |08 causing the engagement of the clutch member 96 with the clutch member 94. The link mechanism Illl, ||2 acting on the arm I |3 will cause a synchronized retraction of the brake shoe |06.

Unless the movement of the door toward its closed position is otherwise arrested, it will continue until it reaches its closed position. Thereupon a suitable member on the door will engage, and hold open, the isolating switch |90 at the opposite end of the channel-shaped support 28. The opening of the isolating switch |90 opens the circuit tothe normally-open pole of the overload switch |88 so that when the door appreaches itsA fully-closed position the draft mechepee-eos Were itI not for the opening ofthe anism isr actuated, as hereinbefore explained, to shift the switch-actuating member |10 to open the circuit tothe electro-magnets and the motor. isolating switch |90 the actuation of the overload switch |88 would cut in the circuit wherebyv the motor is" caused toopen the door, thus returning the door to its fully-open position, instead of checking its movement at its fully-closed position.

1f, however, in the course of its. movement toward a closed position the door 20 should strike an obstruction, the checking of the movement of thev door would be transmitted to the` shaft 5G,

causing an axial movement. thereof against the spring 68.-

would result in a movement. of the member whereupon the switch-actuating member |18 would be shifted to cause retraction of the overload-reversing switchl |88.. The shifting of this switchY |88 would break the circuit to the electro-magnet |84, resulting in retraction-of the contacter switch |82 andthe interlocking switch |92, thereby causing, restoration of the clutch and brake mechanism to its normal position as shown inv Fig. 6.

However, the establishing of contact across the terminals in the dotted lines leading to theY isolating switch |90 would resultv in an energization ofthe electro-magnet |83. Thisv would cause its armature to close the interlocking switch I9 I` and the contacter switch i8 I whereupon the electro-magnet H5 and motor 26 would be simultaneously energized to cause a movement of the door toward its open position, as previously explained.

Wherev the clutch. and brake mechanism 25 is of the type shownv in Fig. 14, the movement of the door would be exactly the same, .under the control of theswitch mechanisms which` have just been described with regard to Fig. 10 for the modification shown in Fig. 6. The only difference would be that the closing of the contactor switch |f8| or |82 wold-i result ln. an energization of the electro-magnets |60 forl either the clutch member 96 or 91', causing an attraction of either the armature |6| or the armature |82 and thereby eifecting the engagement of the respective driving and driven clutch members. Simultaneously with the energization or deenergization of Athe electro-magnets |60, for either of the clutch members 96" or 91', the electro-magnet |49 would be energized or deenergized to effect the operation of the brake. mechanism shown in Fig; 15.

'If either. of the clutch and brake mechanism` modifications shownin Figs. l1 or 15 were employed, the door` mechanism would have the same movements as. already explained under the.` influence of the same Vswitch mechanisms.

Where the modic'ation shown in Fig. 1'1 ls employed 'the energizatlon of the electro-magnet |49 would cause the armature |48 to shift the lever |31 into the full-line position shown i'n Fig. l1. would permit the spring |34 to shift the driving clutch member |28fi'nt`o cointactl with vthe driven clutch member |29 whichwould locate the lever |30 in the full-line position shown in Fig. l1. Upon the` opening of the control circuit to del-energize the electro-magnet |49 the spring` |39 would cause a shifting of .the lever |31. into the position shown in dotted outline whereupon the rollerl cam |42, engaging the cam surface |41 on therlever |38, would retract the driving clutch member |28 from contact with the drive-n clutch member |29. v

Where the modification, shown in Fig; 11, `isI used in connection with the spiral screw type draft means 22, and the door were to meet an obstruction as it moved toward its closed position, the axial shifting of the shaft 56 not only would cause the member |69 to shift the switchactuating member |10, to operate the overload switch |88, but the movement of the member |69 would be transmitted through the arm |58, link |51, and bell-crank lever |56 to increase the tension on the spring |39. This would not only ensure the disengagement of the driving clutch member |28 but also cause an increased pressure of the spring |39 to urge the brake shoe |06 against the drum 98.

Where the modified form of clutch mechanism shown in Fig. 15 is employed, the engagement and disengagement of the driving clutch member |28", with the driven clutch member |29', is controlled directly, whereas the retraction or application of the brake shoe |96 is controlled by the de-energization or energization of the electromagnet |49. The shifting of the bell-crank lever |55, when the shaft 56 has been given an axial movement against the action of the spring 68 due to the door meeting an obstruction as it moved toward its closed position, yalso would be effected as hereinbefore set forth.

When either of the clutch or brake mechanism modifications shown in Figs, 6 and 14 is employed, in connection with the chain and sprocketmeans 23, the operation under the action of the switch mechanisms shown in Figs. and 16 is the same as hereinbeforedescribed, except that, when the door meets an obstruction, as it moves toward itsclosed position, the normal tension on the belt 82 is reversed from the situation shown in full outlines in Fig. 9 so that the arm |69v is shifted against the action of the spring lllthereby causing a movement of the switch-actuating member |10'.

Other variations and modifications in the details of structure and arrangement of the parts may be resorted to within the spirit and coverage of the appended claims.

` I claim:

1. The vcombination with a door shiftable between a vertically-disposed closed position and an overhead open position, of overhead horizontal tracks, brackets attached to said door and supporting rollers for travel on said tracks, a motor, a shaft extending parallel to said tracks and having a spiral thread formed thereon approximately the length :of said tracks, said shaft being axially shiftable in its bearings, resilient means normally urging saidl shaft toward one extreme axial position, a follower block connected to said door and formed to mesh with the thread on said shaft so as to traverse said shaft when it is rotated and -thereby shift said door between its closed and open positions, a driven clutch member and va brake shoe drum connected to rotate with said shaft, a co-axially mounted co-acting l driving clutch member connected to said motor,

said clutch members being axially shiftable relative to each other into and out of driving engagement, a brake shoe, a second resilient means normally urging said brake shoe into engagement with said brake drum, a third resilient means normally urging the axially-shiftable clutch member into engagement with the other said clutch member, a lever for shifting said shiftable clutch member against the action of said third resilient means, a second lever connected to said brake shoe, co-acting cam elements on said levers arranged so that said clutch lever is retracted when said brake-shoe lever is actuated by said brake'- shoe resilient means, electro-magnetic means connected to retract said brake-shoe lever when said means is energized, an electrical circuit connecting said electro-magnetic means and said motor with a source of power, means on said shaft adapted to actuate a circuit breaker for said circuit when said shaft is shifted axially against the action of said first-mentioned resilient means, a bell-crank lever having one arm thereof vpositioned to press against the end of said brake-shoe resilient means, and a link mechanism connecting the other arm of said bell-crank lever to said circuit-breaker actuating means'whereby the axial shifting of said shaft increases the compression of said brake-shoe resilient means.

2. The combination with a door shiftable between a vertically-disposed closed position and an overhead open position, of overhead horizontal tracks, ra shaft extending parallel to said tracks and lhaving a spiral thread formed thereon approximately the length of said tracks, a follower block connected to said door and formed to mesh with the thread on said shaft so as to traverse said .shaft when it is rotated `and thereby shift said door between its open and closed positions, a housing mounted at the end of one of said tracks and providing a bearing for said shaft, a sleeve keyed to said shaft, a tubeconcentrically arranged with said shaft and journaled on said housing and having telescopic engagement with said sleeve, means connecting said tube rotatively with said shaft but permitting relative axial movement of said shaft and tube, a cap on the end of said tube, ya spring interposed between said cap and said sleeve end to normally urge said shaft toward one extreme axial position, a driving clutch member rotatably mounted on said tube and -connected to said motor, a driven clutch member keyed to saidv tube, said clutch members being axially shiftable relative to each other into and out of cooperative engagement, means for causing the relative shifting of said clutch members, a spring normally urging said clutch-shifting means in one direction, electro-magnetic means connected to actuate said clutch-shifting means in the opposite direction, and a switch.- controlled circuit connecting saidl electromagnetic means and said motor with a source of power. f

3. The combination with a door, of means for guiding the door in movement through a predetermined path, a rotatable shaft, means connecting said shaft with said door whereby rotation of said shaft will effect movement of said door, a brake normally applied to said shaft for securing said shaft against rotation, an electric circuit, a motor in said circuit, a normally disengaged clutch including a driving clutch member connected to said motor land a driven clutch member coaxial with said driving clutch member and connected to said shaft, one of said clutch members being-axially shiftable into and out of engagement with the other clutch member, coacting levers connecting the axially shiftable clutch member and said brake whereby said clutch may be engagedland disengaged when said brake is respectively disengaged and engaged, and electromagnetic means in said circuit connected to actuate said levers to disengage said brake and engage said clutch when said circuit is closed.

4. The combination with a door, of means for guiding the door in movement through a predetermined path, a rotatable shaft, means connecting said shaft with said door whereby rotation of said shaft will effect movement of said door, a brake normally applied to said shaft for securing said shaft against rotation, an electric circuit, a motor in said circuit, a bevel pinion connected to said motor, a pair of coaxial driving clutch members having bevel gears formed on their opposed faces meshing with said pinion, a pair of driven clutch members connected to said shaft and coaxial With said driving clutch members and shiftable axially into and out of engagement therewith, a pair of levers connected to said driven clutch members, resilient means connected to said levers to normally disengage said clutch members, links connecting said clutch levers with said brake to effect the disengagement and engagement of said brake with said shaft when said clutch members are respectively engaged and disengaged, and electromagnetic means in said circuit and connected to said levers to selectively engage one of said driven clutch members with one of said driving clutch' members against the action of said resilient means.

5. The combination with a door, of means for guiding the door in movement through a predetermined path, a rotatable shaft, means connecting said shaft with said door whereby rotaf tion of said shaft will eiiect movement of said door, a brake normally applied to said shaft for securing said shaft against rotation, an electric circuit, a motor in said circuit, a'bevel pinion connected to said motor, a pair of coaxial driving clutch members having bevel gears formed on their opposed faces meshing with said pinion, a pair of driven clutch members coaxial with said driving clutch members and connected to said shaft, said driving clutch members being axially shiftable into and out of engagement with said driven clutch members, resilient means normally urging said clutch members out of engagement, electromagnetic means connected in vsaid circuit and carried by said driven members for selectively engaging saidclutch members, and other electromagnetic means in said circuit for disengaging said brake.

6. The combination with a door, of means kfor guiding the door in movement through a predetermined path, a rotatable shaft, means connecting said shaft with said door whereby rotation of said shaft Will eifect movement of said door, an electric circuit, a motorin said circuit, a driven clutch member connected to said shaft, a driving clutch member connected to said motor and shiftable into and out of engagement with said driven member, a lever for shifting said driving member, resilient means normally urging said driving member toward engagement with said driven member, a brake drum connected to said shaft, a brake shoe movable into and out of engagement with said drum, a lever for moving said shoe, second resilient means urging said shoe into engagement with said drum, electromagnetic means in said circuit and connected to said brake lever for disengaging said brake shoe and said drum, and coacting cam elements on said levers arranged to synchronize the engagement and disengagement of said clutch members respectively with the disengagement and engagement of said brake shoe and brake drum.

KARL E. JoHANsON.

REFERENCES CITED UNITED STATES PA'I'ENTs Number Name Date 1,102,921 Hodges July 7, 1914 1,378,146 'Iaigman- May 17, 1921 1,384,464 Hemleb July 12, 1921 1,405,640 Taigman Feb. 7, 1922 1,471,454 Dolan etal. Oct. 23, 1923 1,472,864 Burns Nov. 6, 1923 1,651,985 Allen Dec. 6, 1927 1,745,990 Goldman Feb.` 4, 1930 1,897,391 Kelly Feb. 14, 1933 1,972,695 Staude Sept. 4, 1934 2,000,515` Gross May 7, 1935 2,056,174 Earhuff et al Oct. 6,1936 2,070,058 McCloud Feb. 9, 1937 2,099,191 Blodgett Nov. 16, 1937 2,253,170 Dunham Aug. 19, 1941 2,315,571 Wilder Apr. 6, 1943 2,335,336- Zoller Nov. 30, 1943 2,378,262 Vallen June 12. 1945 

